Monday, 6 October 2008: 3:30 PM
George R. Brown Convention Center, 361C
Reclamation of mined soils could restore soil quality and ecosystem productivity while sequestering C. Potential for carbon sequestration of the reclaimed mined lands restored for forest and grassland is well documented. However, limited data exist with regard to the C storage and dynamics in intensively managed mined land systems such as prime farm lands. A study was conducted to evaluate the effects of intensive management, including annual application of cow manure and mineral fertilizers, on soil organic carbon and microbial biomass carbon of 20-yr old reclaimed mined soils under conventional till corn (Zea mays L.) for silage and intensively managed pastures for 8 yrs in eastern Ohio. Soil organic carbon pool of the top 50 cm layer was 66, 68, 75, 86 and 99 Mg C ha-1 for undisturbed conventional till corn, undisturbed pastures, reclaimed conventional till corn, reclaimed pastures and undisturbed hardwood forest, respectively. Stable C isotope (δ13C) analysis of soils from corn, pastures and forest sites ranged from -23.13 to -24.80, -24.50 to -26.50 and -25.5 to -27.00‰, respectively. There were no significant differences in the δ13C composition of corn and pasture soils, suggesting minimum contribution of corn biomass into soil organic carbon storage of tilled corn sites, probably due to corn biomass removal for silage. Mineralizable and microbial biomass carbon of the top 10 cm layer was significantly greater in reclaimed pastures than the reclaimed corn soils. These findings illustrate the benefits of organic inputs and intensive management in mined land restoration and carbon sequestration.